Continuous wire-drawing machine



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Filed Nov. 19, 1956 INVENTOR. John H. HitchcocK BYE United States Patent2,909,275 CONTINUOUS WIRE-DRAWING MACHINE John H. Hitchcock, Worcester,Mass., assignor to Morgan Construction Company, Worcester, Mass., acorpora- I fion of Massachusetts Application November 19, 1956, SerialNo. 623,149

4 Claims. (Cl. 205-14),

This invention relates generally to continuous wiredrawing machinery andmore particularly to apparatus for changing torque transmission to ablock in response to changes in die reaction. This a continuationdn-partof patent application Serial Number 267,276 filed January 19, 1952, nowabandoned. I

A continuous wi-re drawing machine consists of a plurality of revolvingblocks each connected to a common, driven jack-shaft by a clutch whosetorque transmission characteristics may be changed as desired. It isnormal practiceto operate such a machine with the application of a fixedtorque being determined by the particular drafting schedule, the size ofthe wire, etc. For a particular drafting schedule with a given wiresize, the established back-pull at each die, determined by the torquetransmitted to the preceding block, will remain constant provided thewire characteristics at the position, such as diameter and hardness,remain the same. However, the established back-pulls will increase ordecrease with any increase or decrease of the initial wire diameter, forinstance. If the wire variation is extreme, the back-pull may increaseto a value that will cause the wire to break or, conversely, maydecrease to a value that will develop slack wire with subsequent wirebreakage when the slack is suddenly taken up. The present inventionobviates these difliculties, as will be evident from the descriptionwhich follows.

2,909,275. Patented Oct. 20, 1959 referring to the following descriptiontaken in connection drawing machine makes use of hydraulic clutches totransmit torque from a main jacleshaft to the individual blocks. Eachblock is served by its own hydraulic clutch and the torque transmissionof this clutch can be con trolled by regulation of the pressure in thefluid pass ing through the clutch According to the present invenf tion,this is done by inserting a regulating valve between the clutch and thefluid discharge point and by controlling the opening of this valve inresponse to the forces acting on the preceding die.

Referring to the drawing, the apparatus of the invention, generallydesignated 10, is shown in use with elements of a wire-drawing machine,these elements being a die 11, a block 12, and a hydraulic clutch .13.The hydraulic clutch is of the type shown and described in the patent ofMorgan et al. described above which clutch It is therefore anoutstanding object of the invention Furthermore, it is an object of thepresent invention to provide an apparatus for controlling the torquedelivered to the first drawing block of a continuous wire machine as ameans of maintaining the back-pull preceding each die throughout themachine at a constant value regardless of the possible physicalvariations of the wire. A- further object of this invention is toprovidean apparatus associated with the first die of a multi-blockWire-drawing machine that will control the torque transmission to thefirst block of themachine in response to the reaction of said first die.1

.Another object of .the invention lies in the provision of means forpreventing extreme changes in back-pull between any block and itssucceeding die throughout a minus-block, continuous wire-drawing machineupon transmits torque in proportion to the pressure drop across theclutch. One side of the clutch 13 is connected to the block through agear transmission 14 and the other side is connected by worm and pinionmeans 15 to an electric driving motor 16. Fluid enters the clutch 13through a conduit 17 which is connected to a source of fluid, not shown;the clutch acts as a pump causing the fluid to flow through a conduit 18back to the source. It is the nature cf such a hydraulic clutch totransmit greater torque from the driven side to the output side when thepressure in the fluid is increased. A regulating valve :19 is insertedin the conduit 18 to control the pressure of the fluid. The valve 19 isof a well-known type for controlling pressure and has a valve member 20which can be moved toward a valve seat 21 or away from it by themovement of a stem- 22.

The output conduit 18 of the hydraulic clutch is con-' nected to theinlet of 'the regulating valve 19 and the outlet of the valve isconnected to a conduit 23 by which the fluid is returned to the source.The valve 19 has a cylindrical body 24 within which is sl-idablymounted-a piston 25 which is provided with a bleeder passage '26. To onesidevof the piston 24 is attached the valve member 20 which-is adaptedto move toward and away from contact with the valve seat 21. Tothe'other side of the changes in physicalcha'racteristics of the wirereceived by; the machine.

apparatus -for controlling the pressure of fluid passing.

through the hydraulic clutches of a wiredrawing machine in iesponse todie reaction. ,1 1

Arlthoug-h the novel features which are characteristic of this inventionbe particularly pointed out in the claimsappended hereto, the inventionitself, as toits objects and advantages, the mode of its operation andthe manner. of its'org'anization will'be better understood by Anotherobject of thisinvention is the provision of piston 25 is attached therod22which is 'slidably mount ed in a guide'recess 27. 7 A'coil spring 28surrounds the rod 22 and biases the piston 25 toward a position in whichthe valve member 20 is in contact with the seat 21 and the valve isclosed. The portion of the cylinder bodyrounded by a valveseat 38. Aconduit 39 is connected to the outlet 37, whereby the fluid passingtherethrough returns to the source of fluid. Attached .to the center ofthe diaphragm 36 and'shaped'fto fit the valve seat 38 is a valve. member41. 011 the other side of the d-iaf' phragm in the chamber 34' issituatedacoil spring 42 which extends between the diaphragm and anadjustable plug 43 threaded into the top of the valve 33. The valve seat38, the valve member 41', the spring 42', and the plug 43 are inalignment. An inlet opening 44 is provided, into the. chamber 341 and tothis opening. s connected a conduit, 45., 1

The conduit 45 has connected thereto a gage 46 for indicating fluidpressures within the conduit. The conduit 45 is also connected, toconduits 47' and; 48 which lead to a die support 49.. The die support 49is of a generally U-shaped configuration, having two legs 51 and 52,respectively, and an intermediate portion 53. Thedie 11 is fastened tothe center of the, intermediate pornon, the path of the wire being theaxis of symmetry for the support and its. associated parts. One sideonly of the support 49 and the elements associated therewith will bedescribed, it being understood that the other side will be imilar inconstruction and function. The leg 51 of the support 49 is formed with abore 54 parallel to the direction of wire travel and in this bore isslidably mounted a piston 55, the bore and piston constituting a controlvalve. The support 49 is slidably mounted on the bed of the machine byany of several well-known means while the piston 55 is fixed immovablyto a portion 56 of the bed, a resilient means such ascoil. spring 57 maybe interposed between the die support and a portion of the bed. It canbe seen then that the support is free to move in the direction of thewire travel and. that the walls of the bore 54 are free to sliderelative to the fixed piston 55. The piston 55 has a reduced centralportion 58 which divides the piston into-two end portions 59 and 61,respectively. The end portions fit snugly in the bore 54, whereas. thereis a considerable annular space between the reduced portion and thebore. A passage 62 passes through the die support, into the bore 54 inthe end thereof adjacent the portion 59 of the piston; it is to thispassage 62 that the conduit 48 is connected. Passages 63 and 64 alsopass through the support into the bore54 in the intermediate portionthereof. The passages 63 and 64. open into the bore at points spacedfrom one. another by a distance slightly greater than the distancebetween the two end portions 59 and 61 of the piston. 55, so that theend; portions of the piston may cover both passages at one time, but mayuncover one of them by a slight axial movement of the piston. Theopening of the passages 63 and 64 into, the bore may comprise annulargrooves in the wall of the bore. A passage 65 passes through the pistonfrom the surface 66 of the head and opens on the surface of the, reducedportion 58 thereof. The external opening of the passage. 63 is connectedto a, source. of fluid under pressure, preferably a source of constantpressure and one which. is separatefrom the source used in the hydraulicclutches of the machine. The external opening of the passage 64 isconnected to a sump tank of the fluid source.

The operation of this embodiment is as follows: When no wire is passingthrough the die, the spring 57 holds support 49 in such. a position thatport 64 opens into the annular space surrounding the reduced portion 58ofthe piston and thus: provides direct communication between bore 54 andthe fluid source which remains at atmospheric pressure. Port 63connected to the high pressure source is blocked by piston end 59. Whenwire enters the die and the force requiredfor drawing is applied tosupport 49, the latter moves slightly in the direction of drawing,compressing spring 57 and closing port 64. Fluid then is trapped betweenbore 54 and head 66, and is subjected to a pressure which is directlyproportional to the drawing force. This pressure is indicatedby gage 46,and istransmitted to the upper chamber 34 of the diaphragm-type pilotvalve 33. Because fluid leakage will occur slowly. through the smallclearance space'between piston55 and'bore 54, support 49 willtendtogmove very slowly in, the direction of wire travel. When thismotion proceeds far' enough to open port 63 to the annular passagearound reduced portion 58 of the piston, fluid under pressure entersthrough port 63 and restores support 49 to its normal operating positionby the pressure on the head 66.

The fluid pressure, proportional to drawing force and transmitted tochamber 34, provides a nominal setting for pilot valve 33, which in turnestablishes a level of pressure inconduit 31. This controls the openingof valve 19 and establishes through conduit 18 a level of pressure and.torque'in the hydraulic clutch which corresponds tothe prevailing valueof drawing force. If the drawing force is increased by an increase indiameter of the entering wire, for instance, the fluid pressure is.increased in conduit 45 and chamber 34; and, through the resultingautomatic readjustment of valves 33 and 19, the pressure and torquedeveloped by the hydraulic clutch are increased to match the increaseddrawing force. This process is fully automatic throughout a limitedrange of variation of drawing force; manual adjustment of plug 43 servesto regulate pressure and torque for large changes of drawing force, suchas are required when drawing of one order has been completed and a newschedule is undertaken involving different reduction or wire of adifferent character.

Similarly, if the drawing force is decreased by a diminution of enteringwire size, for instance, the fluid pressure in chamber 34 is decreased,and through automatic readjustment of valves 33 and 19 the pressure andtorque at the hydraulic clutch are decreased to match the smallerdrawing force. Thus this embodiment likewise serves to preventsignificant and serious changes of back pull in the wire leaving theblock which otherwise would result from changes in drawing force.

The diaphragm type, differential-pressure valve 33 serves essentially asa pilot valve to control the pressure above piston 25 of the mainpressure control valve 19. The pilot valve 33 deals with only a smallquantity of fluid, as compared to main valve 19, and for this reason canachieve a close regulation of pressure in discharge duct 18 with onlyslight motion of diaphragm 36. Consequently only slight motion of thedie support 49, withrespect to the pistons fixed in abutment 56, isrequired forpressure control. However, leakage of fluid may occur,allowing piston 66 to approach the end of bore 54. In this event passage63 gains access to the portion ofreduced diameter 58 on piston 61,allowing fluid under pressure to enter through inlet 63 and returningsupport 49 to its normal position with inlet 63 closed. Similarly, ifsupport 49 were to move too far in the opposite direction, because offluid leakage from inlet 63 into bore 54, the outlet passage 64 wouldgain access to the, reduced portion 58, allowing excess fluid to escapeandrestoring support 49 to its normal position.

While certain novel; features of the invention have been shown anddescribed and are pointed out in the annexed claims, it must beunderstood that various omissions, substitutions, and changes in theforms and details of the device illustrated and in its operation may bemade by those skilled in the art without departing from the essence. ofthe invention.

The invention having thus been described, what is claimed as new anddesired to secure by Letters Patent 1s:

1. A continuous wire-drawing machine, comprising a base, a die, a blockfollowing said die, a driving means for said block, a hydraulic clutchconnecting the driving means to the block, said clutch having thecharacteristic of torque transmission dependent upon the differentialfluid pressure across the clutch, a support for said die, said supportcomprising one element of a control valve of a hydraulic system, saidsupport being mounted on: said base so that it may move relative to thebase, in line. with wire travel in response to changes in die reaction,

another element of the control valve fixed relative to the,

base and cooperating with the said one element, a valve regulating thepressure of fluid in said clutch, the hydraulic control system beingconnected to the valve so that the pressure may change in response tomovement relative to the base of said support.

2. A continuous wire-drawing machine, comprising a base, a die mountedon the base, a block mounted on the base and following the said die, adriving means for said block, said means including a clutch, said clutchhaving the characteristic of torque transmission dependent upon thedifierential in fluid pressure across the clutch, a die support having abore, said bore comprising one element of a control valve, said supportbeing mounted on said base so that it may move relative to the base inline with wire travel in response to changes in die reaction, a pistonelement of the control valve fixed relative to the base and located forsliding within the said bore, a second valve regulating the pressure offluid in said clutch, the control valve being connected to the secondvalve so that the pressure across the clutch may change in response tomovement relative to the base of said support.

3. A continuous wire-drawing machine, comprising a die, a blockfollowing said die, the die and block being the first die and block,respectively, of the machine, a driving means for said block, ahydraulic clutch connecting the driving means to the block, said clutchhaving the characteristic of torque transmission dependent upon thedifferential in pressure across the clutch, a hydraulic control system,a control valve for said system, a support constituting a movableelement of said control valve slidably mounted on said machine, the diemounted on said,

support, resilient means biasing said support, the support being movablein response to changes in die reaction, a valve regulating thedifferential in pressure across the clutch, the hydraulic control systembeing connected to Said regulating valve so that the said ditferentialin pressure changes in response to movement of the support.

4. A continuous wire-drawing machine, comprising a base, a die, a blockfollowing said die, the die and block being the first die and block,respectively, of the machine, a driving means for Said block, ahydraulic clutch connecting the driving means to the block, said clutchhaving the characteristic of torque transmission dependent upon thepressure in the fluid passing therethrough, a hydraulic control system,a control valve for said system, a support having a bore constituting anelement of said control valve slidably mounted on said base, the diemounted on said support, a piston fixed to the base for cooperation withthe bore, resilient means biasing said support, the support beingmovable relative to the base in response to changes in die reaction, avalve regulating the fluid pressure in said clutch, the hydrauliccontrol system being connected to said regulating valve so that thepressure changes in response to movement of the support.

References Cited in the file of this patent UNITED STATES PATENTS1,637,109 Honig July 26, 1927 2,003,475 Shipp J1me 4, 1935 2,205,213Lessmann June 18, 1940 2,263,246 Morgan Nov. 18, 1941 2,370,481 MorganFeb. 27, 1945 2,432,191 Chilton Dec. 9, 1947 2,462,558 Scheuermaun eta1. Feb. 22, 1949 2,646,150 Hobbs July 21, 1953 2,748,925 Wilson June 5,1956 FOREIGN PATENTS 264,039 Switzerland Dec. 16, 1949

